The invention relates to a device for separating a sheet pile during a running operation of a pile-forming sheet-processing machine, in particular, a sheet-fed printing machine, and to a sheet-processing machine including the device.
In a pile-forming machine, the pile that has been produced must be removed from time to time. For a continuously operating machine, this should take place with the least possible disruption of production and without damage to any of the sheets.
For this purpose, prior to the removal of a finished pile or stack (also known as a main pile or stack), sheet catchers, which are simple separating elements, are pushed into the front region of the sheet pile, so that the next following sheet no longer descends with the leading edge thereof completely onto the main stack. Then, during the running operation, an auxiliary pile carrier in the form of a board, which is fastened to guides, is pushed into the gap that has been kept open by the sheet catchers on the front side of the pile, and carries the sheets which accumulated in the interim on the sheet catchers. The main pile, thus separated during running or continuous operation, can then be removed from the machine or be used to form so-called hurdle piles.
Due to pushing in the auxiliary pile carrier, the sheets which have accumulated on the sheet catchers may slip backward, so that a production run has to be interrupted. Particularly when the machine is operating in the hurdle mode, the problem arises that the trailing or rear-edge stops securing the pile have to be swung upwardly in order to push the boards in. The sheets lying on the sheet catchers thereby slip over the rear or trailing edge of the sheet pile, so that a neat pile can no longer be formed and, if desirable or necessary, the process has to be interrupted.
In order to prevent this from happening, in fact, a method and a device have become known heretofore, from the published German Patent Document DE 43 17 357 C1, wherein support beams and a crossbar are articulatedly connected to a traverse fastened to a sheet brake, and so-called sheet high-holders swing into the region of the pile when a pile board is pushed in. In this regard, however, the pile is fanned open by the inwardly pivoting sheet high-holders, and damage to the sheets may occur.
It is accordingly an object of the invention to provide a device of the type mentioned in the introduction hereto, which automatically prevents the sheets from slipping out of place when an auxiliary pile carrier is pushed in.
With the foregoing and other objects in view, there is provided, in accordance with one aspect of the invention, a device for separating a sheet pile during the running operation of a pile-forming sheet-processing machine, comprising a separator which, when an auxiliary pile carrier is pushed into a sheet pile to be separated, is movable between a rear upper edge of the sheet pile to be separated and a following sheet for a new sheet pile, for the purpose of lifting a rear lower edge of the new sheet pile at least into an effective range of a rear sheet stop.
In accordance with another feature of the invention, the separator is pivotable inwardly between the sheet pile to be separated and the following sheet for the new sheet pile, a rear edge of the new sheet pile being simultaneously lifted, the separator being pivotable about a horizontal axis extending transversely to a travel direction of the sheet.
In accordance with a further feature of the invention, the separating device includes a lever to which the separator is connected via a linkage, the lever being actuatable by the auxiliary pile carrier for pivoting the separator inwardly, when the auxiliary pile carrier is pushed inwardly.
In accordance with an added feature of the invention, the lever is disposed adjacent the sheet pile to be separated and the new sheet pile.
In accordance with an additional feature of the invention, the separator is disposed in the middle of a pile-forming region.
In accordance with yet another feature of the invention, the separator is actuatable counter to a restoring spring force.
In accordance with yet a further feature of the invention, the separator has at least one elongated finger for pivoting inwardly between the sheet pile to be separated and the new sheet pile, the elongated finger being formed as a lifter in a manner that, when pivoting inwardly between the sheet pile to be separated and the new sheet pile, it engages under the new sheet pile and lifts it, and in a fully pivoted-in end position, the rear new pile end lies on the separator, so as to ascend from the pushed-in auxiliary pile carrier to the rear sheet stop.
In accordance with yet an added feature of the invention, in any pivoted-in position, the separator extends obliquely to the new pile, so that, during the inwardly pivoting action, the new pile is prevented from slipping out of place by a forward-acting force component.
In accordance with yet an additional feature of the invention, the separating device includes a lever linkage via which, in addition to the separator being pivotable inwardly, the rear-edge stops are pivotable so as to make it possible for the auxiliary pile carrier to penetrate beyond the rear-edge stops, the rear edge of the new pile being secured at all times.
In accordance with another aspect of the invention, there is provided a pile-forming sheet-processing machine having a device for separating a sheet pile during the running operation of the machine, comprising a separator which, when an auxiliary pile carrier is pushed into a sheet pile to be separated, is movable between a rear upper edge of the sheet pile to be separated and a following sheet for a new sheet pile, for the purpose of lifting a rear lower edge of the new sheet pile at least into an effective range of a rear sheet stop.
In accordance with a concomitant feature of the invention, there is provided a pile-forming sheet-fed printing machine having a device for separating a sheet pile during the running operation of the machine, comprising a separator which, when an auxiliary pile carrier is pushed into a sheet pile to be separated, is movable between a rear upper edge of the sheet pile to be separated and a following sheet for a new sheet pile, for the purpose of lifting a rear lower edge of the new sheet pile at least into an effective range of a rear sheet stop.
In the device according to the invention and in the sheet-processing machine and sheet-fed printing press according to the invention, the aforementioned object of the invention is achieved in that a separator is provided, which, when an auxiliary pile carrier is pushed inwardly, is moved between a rear upper edge of the sheet pile to be separated and a new sheet pile formed by following sheets and which lifts the rear lower edge of the new pile at least into the effective range of the rear sheet stop of the pile-forming region.
For this purpose, provision may be made for the separator to be pivotable from below about a horizontal axis running transversely to the sheet running direction, inwardly between the pile to be separated and the new pile, the rear edge of the new pile being simultaneously lifted.
In order to actuate the separator automatically when the auxiliary pile carrier is pushed inwardly, provision may be made for the separator to be connected via a linkage to a lever which, when the auxiliary pile carrier is pushed inwardly, is actuated by the latter and pivots in the separator.
So as not to obstruct the piles, provision is made for the lever to be arranged adjacent the piles.
In a further development of the invention, provision is made for the separator to be arranged in the middle of a pile-forming region.
In order to avoid damage to the rear edge of the new pile when the auxiliary pile carrier is lowered, provision may, furthermore, be made for the separator to be actuated counter to a restoring spring force.
In another development of the invention, there is provision for the separator to have, for pivoting inwardly between the piles, at least one elongated finger formed like a lifter, so that, when pivoted into the pile-forming region, it engages under the new pile and lifts it, and, in a fully pivoted-in end position, the rear pile end lies on the separator so as to ascend from the pushed-in auxiliary pile carrier to the rear sheet stop.
In order to prevent the new pile from slipping out of place when the auxiliary pile carrier is pushed in, in a further development there is a provision, the in each pivoting-in position, the separator extends obliquely to the new pile, so that, during the inwardly pivoting action, the new pile is prevented from slipping out of place by a forward-acting force component.
Furthermore, in a development of the invention, via a lever linkage, in addition to the separator being pivoted inwardly, the rear-edge stops are pivoted away so that it is possible for the auxiliary pile carrier to penetrate past the rear-edge stops, the rear edge of the new pile being secured at all times.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a separating aid for a sheet-pile change in a printing machine, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, wherein: